QSpace Collection:http://hdl.handle.net/1974/5539
Tue, 03 Mar 2015 18:49:23 GMT2015-03-03T18:49:23ZThe Donnely Zone Porphyry Deposit in Northwestern British Columbia: A Study of Petrography, Lithogeochemistry and Sulphur Isotopeshttp://hdl.handle.net/1974/12449
Title: The Donnely Zone Porphyry Deposit in Northwestern British Columbia: A Study of Petrography, Lithogeochemistry and Sulphur Isotopes
Authors: Smyth, William
Abstract: The Donnelly Zone copper-gold porphyry deposit is located within the GJ/Kinaskan Project mineral claims in northwestern British Columbia. The GJ/Kinaskan Project property is situated on the northern end of the Stikine Terrane, within the Intermontane Belt of the Canadian Cordillera. Late Triassic to early Jurassic diorite-monzonite-monzodiorite intrusions are associated with Cu-Au mineralization. Exposure at the Donnelly Zone largely displays the Stuhini Formation, which contains the majority of the mineralized subvolcanic intrusions.
In field drill core analysis along with petrographic, lithogeochemical and sulfur isotope analysis was conducted in lab on collected samples. Petrographic analysis indicates that several distinct intrusions exist and pervasive quartz, calcite, sericite and pyrite alteration occurs in both the host and intrusive units. The porphyry deposit is characterized as transitional silica saturated alkalic to medium K calc-alkalic. There is an evident relationship between the proximity to the intrusive units and an increasing weight percentage of chalcopyrite. A zonation of sulfur isotope values is non-apparent.
Due to the complex nature of the deposit region, the research of this report can aid in further exploration of the Donnelly Zone, where ultimately a decision is required for whether the property is economically viable for mining practices.Sat, 13 Sep 2014 04:00:00 GMThttp://hdl.handle.net/1974/124492014-09-13T04:00:00ZA Solid Inclusion Study in Gem-Quality Cordierites From the Ghost Lake Occurrence, Northwest Territorieshttp://hdl.handle.net/1974/12382
Title: A Solid Inclusion Study in Gem-Quality Cordierites From the Ghost Lake Occurrence, Northwest Territories
Authors: Joyce, Michael
Abstract: The unique optical properties exhibited by cordierite necessitate the precise orientation of the uncut crystal prior to the faceting of an attractive gemstone. Rough specimens of gem-quality cordierite collected by Brad Wilson from the Ghost Lake locality in the Northwest Territories, Canada, are occasionally of suitable quality for faceting and fashioning in jewelry. Occurring sporadically in pods throughout the banded gneisses in the area, these iolite specimens are commonly of a cloudy appearance and contain many small needle-like inclusions. For numerous grains, the orientation of the optic axes were determined via the collection of extinction data on a rotating spindle stage further augmented by the EXCALIBR II program. Optical data determined via polarizing microscope and the EXCALIBR II computer program prove the majority of cordierite specimens to be optically positive with a 2Vz≈87°. The solid inclusions were all found to be coplanar along (010) of the host crystal and are elongate along two dominant trends, each oriented approximately 22.5° on either side of the crystallographic a-axis. SEM analysis of the platelet-type inclusions resulted in the identification of pyrrhotite, chalcopyrite, pentlandite, and a Fe-oxide phase. The consistent orientation of the solid inclusions amongst various grains from the Ghost Lake occurrence indicates that the probable control of this orientation is the atomic structure of the host cordierite, rather than metamorphic or other controlling factors. The solid inclusions may have originated during retrograde metamorphism and preferentially aligned on (010) as a result of planar weaknesses previously developed along this crystallographic plane.Tue, 26 Aug 2014 04:00:00 GMThttp://hdl.handle.net/1974/123822014-08-26T04:00:00ZA Comparative Analysis of Contaminated Streambed Sediment Mineralogy Using Bulk X-Ray Diffraction and Mineral Liberation Analysis.http://hdl.handle.net/1974/12049
Title: A Comparative Analysis of Contaminated Streambed Sediment Mineralogy Using Bulk X-Ray Diffraction and Mineral Liberation Analysis.
Authors: McKenzie, Amanda
Abstract: The historic and highly contaminated Ely Copper Mine (Vershire, Vermont, USA) operated from 1821 to 1905. Due to unregulated mining practices and an absence of environmental planning, the Ely Mine site contains extensive acid rock drainage. As a result, the site was registered on the National Priority List by the Environmental Protection Agency in 2001. Transition metal concentrations are high in Ely Brook sediments, with copper being the most dominant. In this thesis, modal mineralogy of contaminated streambed sediments from the Ely Mine was determined by a new quantitative mineralogical technique known as Mineral Liberation Analysis (MLA), and the results were compared to the more traditional mineral identification method of bulk x-ray diffraction (bulk XRD). Four metal-contaminated streambed sediment samples were analyzed in order to elucidate possible copper hosts. The mineral assemblages, relative weight percentages and potential mineralogical copper sources and sinks were determined. Mineral Liberation Analysis and bulk XRD produced similar mineral assemblages in terms of the dominant phases present. The most abundant minerals in decreasing order include quartz, plagioclase, goethite, hornblende, muscovite, jarosite and chlorite. Mineral Liberation Analysis was able to detect minerals of very low abundance (> 0.01 wt. %), including the ore minerals covellite and chalcopyrite. Several minerals identified using MLA could not be recognized by bulk XRD, including manganese-rich garnets and stilpnomelane. A significant limitation to MLA was distinguishing multiple phases present in highly complex grains and mineral boundaries. Following analysis, the most likely copper sources are chalcopyrite, covellite and an unidentified highly weathered sulphide, whereas the most likely secondary hosts of copper are goethite, jarosite and birnessite.Mon, 21 Apr 2014 04:00:00 GMThttp://hdl.handle.net/1974/120492014-04-21T04:00:00ZEcospace Utilization and Paleoenvironmental Reconstruction of an Upper-Ordovician Carbonate Ramp - Kingston, Ontario Regionhttp://hdl.handle.net/1974/12045
Title: Ecospace Utilization and Paleoenvironmental Reconstruction of an Upper-Ordovician Carbonate Ramp - Kingston, Ontario Region
Authors: Boag, Thomas
Abstract: The Black River and Trenton Group limestone uncomfortably overlie Mesoproterozoic Grenvillian basement and crop out along a 45 km transect to the west of Kingston, Ontario. This represents a deepening-upwards carbonate succession of mixed carbonate/siliciclastic rock deposited in the Ordovician Frontenac Seaway in advance of the approaching Taconic Orogeny. This succession has traditionally been considered a tropical open shelf. However, a marked difference in fossil taphonomy, ecospace utilization, and sedimentary structures supports an alternate model of significant lithological, geochemical and thermal regime heterogeneity between nearshore-offshore environments. Quadrat sampling of the nearshore Black River at Taylor-Kidd Boulevard outcrop reveals abundant preservation of aragonitic body fossils including gastropods, cephalopods, and bivalves. The presence of stromatolites and Tetradium coral are indicative of warm water environments well within photic limits, while wave-rippled surfaces suggest a well-mixed water column. The stratigraphically higher Trenton Group at Lennox Generating Station displays a significant change in fauna. Intact echinoderm stems and solitary Prasopora bryozoans indicate lower energy, quiescent conditions in deeper waters. The fossil assemblage is dominated by calcitic brachiopods, while aragonitic body fossils are rare, often preserved as internal moulds. This change in taphonomy suggests a distinct difference in ocean chemistry possibly due to a tropical thermocline, shifting the depositional environment to cool water conditions. HCS and lam-scram surfaces also exist at this locality, evidence of periodic hurricane-force storms. The stratigraphically highest Prince Edward County outcrop displays evidence of anoxic, restricted settings characterized by Chondrites trace fossils and preserved graptolites. Hardgrounds in this facies imply prolonged periods of non-deposition. Due to the significant taphonomic influences present, ecospace utilization was selected as a robust method to define changes to ecological diversity with water depth as it relies only on presence/absence of genera to fill respective ecological guilds. 23 identified genera occupy 12 different ecospace modes, demonstrating high ecological complexity but limited faunal diversity. Ecospace is dominated at all water depths by suspension feeders, which occupy 71% of the observed feeding strategies. Tiering is predominantly by surficial genera; 75% of specimens lived directly on top of the substrate. There is significant divergence between aragonitic vs. calcitic skeleton composition and ecospace occupancy; only 2 genera of differing compositions (Lingula and Cyrtondonta) occupied the same ecospace, which may suggest selection pressures on skeletal composition. These data supports a more heterogeneous depositional model for the Black River-Trenton succession with significant environmental limiting factors for biota, while reinforcing the utility of ecospace utilization as a robust technique for measuring ecological diversity in taphonomically influenced paleoenvironments.Sat, 19 Apr 2014 04:00:00 GMThttp://hdl.handle.net/1974/120452014-04-19T04:00:00Z